|Introduction to Cell & Molecular Biology (BIOL121) - Dr. S.G. Saupe (firstname.lastname@example.org); Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321|
Activities - Water
Upon completion of this unit you should be able to:
Provide some examples showing the importance of water in living systems.
Describe a water molecule. Draw an electron dot structure for water.
Explain why a water molecule is polar.
Define hydrogen bond.
Define electronegative and give an example of an electronegative atom.
Define cohesion and adhesion. Give examples of each.
Compared to other similar sized molecules, such as ammonia, hydrogen sulfide, and carbon dioxide, water has unique properties. Explain why.
each of the following properties of water, define what is meant and give an
example of the phenomenon especially how the property is biologically
important: (a) liquid at room
temperature; (b) heat of vaporization; (c) specific heat; (d) heat of
fusion; (e) surface tension; (f ) universal solvent; (g) density on
crystallization; (h) compressibility; (i) transparency; (j) inert/reactiveness;
(k) effect on shape of other molecules.
Define solvent and solute. Give an example of each.
Identify the biological functions of water
Define xeric, mesic and hydric. Give examples of adaptations of plants (and animals) to these conditions.
Define acid, base and neutral
Write the equation for the dissociation (ionization) of water, hydrochloric acid, sodium hydroxide, and carbonic acid. Indicate which of these are acids, bases or neutral and explain why.
is defined as the negative log of the hydrogen ion concentration.
Explain what this means.
is the concentration of protons in pure water?
Be able to complete the pH sheet given in class.
Define buffer. Explain how the carbonic acid-bicarbonate buffer system works.
Prepare a concept map using such such terms and concepts as: water, hydrogen bond, polarized covalent bond, polar molecule, cohesion, adhesion, the properties of water, the functions of water, hydrophilic, hydrophobic, solvent, solute, hydrogen ion, proton, buffer, homeostasis, acid, base, hydronium ion, hydroxide ion.
Test Yourself: Answer
the questions at the end of the chapter in the text and/or study guide and/or
textbook web site.
Go to the library (or web) and read some articles about water. Then discuss them with your friends. Some possibilities include:
L.J. Henderson. 1913. Fitness of the Environment. Macmillian, NY.
K. 1997. Water World. Discover. May.
Tape Recording Session:
Get a tape recorder and tape definitions of all the terms used in the chapter. Use each in a sentence. Play back the tape in your headphones as you cruise around campus.
The following is a list of some of the functions of water. Match each to the property(s) that is associated with this function. There may be more than one answer for some.
|Responsible for cell growth||Provides the strengthening agent for plant tissues|
|Aquatic life in cold climates is possible||Leaves loose water (transpiration)|
|Aquatic plants are able to photosynthesize||Lakes are slow to warm up in the summer|
|Cactus plants can be slightly cooler than their environment||It hurts to do a bellywhopper|
|Cell fluids contain a rich diversity of organic compounds||Ice fishing is possible|
|DNA and other molecules shape is partially dependent on this property||Dog�s pant to cool themselves|
|Raindrops are round||Some insects can walk along the surface of a lake|
|Water is a liquid at room temperature||Water moves up a thin tube (capillary action)|
|Farmers spray crops with water before a predicted freeze||.|
Last updated: July 14, 2009 � Copyright by SG Saupe